8.5 GWh of grid-scale battery energy storage is installed in Great Britain, an increase of 70% since Modo’s previous BESS supplier analysis.

Which companies have supplied the most capacity, where are the battery cells for these systems coming from, and how has the landscape changed over the past year?

Key takeaways

• Cell manufacturing is dominated by Chinese manufacturers, now supplying 80% of the market, as Korean manufacturers have fallen away completely.
• CATL has cemented its lead over the past year, supplying 81% of the cells installed since the start of 2024.
• The containerised BESS market, once at risk of becoming dominated by Tesla and CATL, has become more competitive with the entrance of rapidly growing challengers.
• New European and North American manufacturers of AC block units have gained market share over the past year, enabling quicker commissioning times and better resilience.
• Tesla and CATL are still dominant forces in containerised BESS supply, but new entrant Wartsila has installed the most capacity since the start of 2024, 714 MWh, providing the BESS units for Blackhillock, Europe’s largest battery.

First up, let’s establish some terminology that will be used throughout the rest of this article.

Battery cell manufacturer: companies that make battery cells, the electrochemical component of a battery that stores the electrical energy. It’s the part of batteries that determines the energy capacity (MWh).

Battery energy storage system (BESS) supplier: companies that supply containerised battery systems made up of battery cells and other equipment.

Integrator: Integrators are responsible for the equipment and software that tie the various components of a battery energy storage system together. This includes key equipment like the inverter, which determines the rated power of the battery (MW).

New entrants to the BESS supply market are quickly catching up to Tesla and CATL

Tesla and CATL are the two largest suppliers of battery energy storage systems in Great Britain. Together they have supplied 40% of currently installed capacity. Both suppliers continue to enable much of Britain’s buildout, supplying 575 and 343 MWh of capacity, respectively, since the start of 2024. Tesla’s higher buildout rate means that it is now the largest BESS supplier in Great Britain.